Suction stripping duct arrangement for transporting rollers



April 1962 K. HACKER ETAL 3,028,742

SUCTION STRIPPING DUCT ARRANGEMENT FOR TRANSPORTING ROLLERS Filed Dec. 19, 1960 United States @atehi: @hfice 3,028,742 Patented Apr. 10, 1962 3,028,742 SUCTION STRIPiiNG DUCT ARRANGEMENT FOR TRANSPGRTING ROLLERS Kurt Hacker, Stuttgart-Zutfenhausen, and Erwin Kohl, Stuttgart-Weilimdorf, Germany, assignors to Fortuna- Werke Spezialmaschinenfahrih A.G., Stuttgart-Baal Cannstatt, Germany Filed Dec. 19, 1%0, er. No. 76,554 Ciaims priority, application Germany Sept. 3, 1960 Claims. (Cl. 69-40) The present invention relates to a suction stripping arrangement for transporting rollers, and more particularly to a suction stripping arrangement for stripping the transporting roller of a leather splitting machine off waste leather material adhering thereto.

In the shoe industry machines are used by which thin leather sheets are split into a layer of uniform thickness which is used for the uppers of shoes, and into a Waste part which may include small strips, pieces, or particles of the leather. In machines of this type, the workpiece is transported between an adjustable abutment rolier, and a lower resiliently supported pressure roller to move in a plane in which a cutting tool, usually a moving cutter band is located. The used layer of the leather sheet is guided upwardly over the cutting tool, while the waste parts are guided downwardly under the plane of the cutting tool. Such waste parts soil and clog the interior of the machine casing, and it is customary to collect the Waste parts in a chute by which they are guided to a suitable receptacle. strips or layer portions which tend to adhere to the transporting roller, particularly due to electrostatic charges, and are consequently Wound up on the transporting roller where they interfere with the transporting function of the roller.

It has been attempted to remove such adhering waste parts from the transporting roller by rotary brushes, or by blowers. However, brushes are soon filled with Waste particles and inefiective, while blowers have been found unsuitable since the waste particles are blown to other parts of the machine and into the workshop.

It is one object of the present invention to overcome the disadvantages of known arrangements for removing waste particles from transporting devices, and to provide a suction stripping arrangement by which transportingv rollers are cleaned by an airstream produced by suction.

Another object of the present invention is to provide a suction stripping arrangement in which a stream of air is guided in tangential direction against the surface of a transporting roller so that waste particles adhering to the roller and being wound up by the same, are stripped from surface of the roller.

Another obiect of the present invention is to provide a suction stripping arrangement for a transporting roller with a displaceable wall portion which forms a suction gap with the peripheral surface of the roller so that the suction duct can be opened for inspection and cleaning.

A related object of the invention is that the displaceable wall portion of the suction duct will automatically open if waste material clogs the suction gap formed between the displaceable wall portion and the surface of the transporting roller.

With these objects in view, the present-invention is concerned with a suction stripping arrangement which comprises a cutting tool means, such as a moving cutter band; a transporting roller, preferably resiliently mounted, for transporting a material or workpiece, such as a leather sheet to the cutting tool; and a suction duct hav- However, some waste parts are thin ing an index portion with a Wall end portion extending parallel toatangent on a peripheral surfaceportion of the transporting roller and defining a narrow gap with the transporting roller.

When the transported sheet is split by the cutterband, the layer which is to be used is located on one side of 1 the cutter band, while waste parts pass to the other side of the cutter band, and tend to adhere to, and to be wound up on the transporting roller to move toward and into the gap. The holder of the cutter band, the good layer of the cut sheet, and the transporting roller close the inlet portion of the suction duct except for the gap through which all the air enters at high velocity, moving in tangential direction along the roller whose surface moves in the gap in a direction opposite to the flow direction of the air. In this manner, waste material adhering to the rollerand moving in'the gap opposite to the direction of the air flow, is stripped off the transporting roller.

The rapidly moving air stream in the gap effectively strips all waste parts adhering to the transporting rollers from the same so that the waste parts are sucked into the duct, and are sucked into the same. Of course, smaller pieces which are torn olf or cut off the workpiece are directly sucked into the suction duct, In order to obtain a smooth flow of the air into the gap, it is preferred to provide a curved extension of the gap-forming wall end portion of the suction duct, and it is particularly advantageous to make such extension part-circular to have substantially the same radius as the transporting roller so that the air flows into a gradually tappering guide formed by the roller and by the wall extension before it enters the gap. In this manner, turbulence and a peeling-otf of the air from the wall of the inlet duct is prevented.

In the preferred embodiment of the invention, the gapforming wall portion is displaceably mounted on a front wall of the suction duct, the rear wall of the suction duct also extends in substantially tangential direction with respect to the transporting roller, and the side walls of the duct extend to the close proximity of the transporting roller.

The rear wall is directly connected to the holder of the cutting tool, and extends transverse to the working plane in which the workpiece is transported.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing, in which:

FIG. 1 is a fragmentary cross-sectional view illustrating one embodiment of the invention; and

FIG. 2 is a fragmentary schematic side elevation, partially in section, and illustrating the arrangement on a smaller scale.

Referring now to the drawing, a supporting table 1 defines a working plane in which a workpiece, for example in the form of avleather sheet 6 is moved toward a pair of transporting rollers 2 and 3. Roller 2 is turnably mounted on a fixed support, while roller 3 is resiliently mounted and is capable of yielding when thicker portions of the workpiece 6 pass between the rollers 2 and 3. A

cutting tool in'the form of a cutter band 5 moves between the holder parts 9 in the working plane, and splits the workpiece into a useable layer 7 of uniform thickness,

and into a waster part 8. Guide parts it) are mounted in holder 9 and have inclined faces for guiding the split parts of the workpiece, and holder'parts. 9 have corresponding inclined faces.

A suction duct 11 is arranged below the working, plane and has an inlet portion located in the region of the transporting roller 3. The rear wall 12 of the suction duct 11 is secured to the lower holder part 9, and is arranged to continue the inclined surfaces of the lower holder members 9 and 10. A surface portion of roller 3 is located opposite the inclined surfaces of the holder members 9 and 10, and the rear wall 12 is inclined to the horizontal at such an angle as to extend parallel to a tangent of this surface portion of the roller 3, A pair of side walls 12a is secured to rear wall 12 and extends at right angles to the same. The upper ends of side wall 12a have curved edges 12b which are located in close proximity to the ends of roller 3 and follow the contour of the same.

The front wall 13 includes an upper wall end portion 14 which is secured at its lower end 16 by hinge means 15 to the fixed front wall portion 13. Suction duct 11 extends into a collecting container 19 to which the inlet of an exhauster, not shown, is connected so that suction is applied to suction duct 11.

The displaceable end portion 14 of the inlet portion of the suction duct has lateral edges which are slideable on side walls 12a and preferably provided with sealing means. The upper end of the wall 14 has a curved extension 14a, illustrated to be part-circular, and having substantially the same radius of curvature as roller 3, or a somewhat greater radius.

A resilient arresting catch means 17 holds wall end portion normally in the position shown in solid lines in which wall 14 extends parallel to a tangent on the peripheral surface of roller 3 which is located opposite wall 14. In this position, wall 14 defines a narrow gap 18 with the peripheral surface of the roller.

Since the work table 1, the workpiece 6, the layer 7, the cutter band and the holder 9 extend across the inlet of suction duct 11, all the air which is sucked into the suction inlet portion, must pass through the narrow gap 18 which extends along the entire axial length of roller 3. Roller 3 rotates in the direction of the arrow to transport the workpiece towards the cutter band 5, and consequently the gap-forming surface portion of roller 3 moves in a direction opposite to the direction of the air which is drawn through the gap 18 into the suction duct, as indicated by arrow 11a. The surface of roller 3, and a curved extension 14a form a guide for the air so that the same enters gap 18 without turbulence. Due to the fact that all the air must pass through the nan-ow gap 18, the velocity of the air is very high in gap 18 as compared with its velocity in the main portion of duct 11. Furthermore, the air moves in the gap in tangential direction to the peripheral surface of the roller, and consequently exerts a stripping action on waste particles adhering to the roller and being carried into the gap. During operation, a leather sheet is split by the cutter band 5, and while a great part 8 of the waste layer may directly pass into suction duct 11, some waste particles, pieces, or strips 8a adhere to the roller surface, and are carried toward the gap, However, the rapidly moving air stream 11a strips such particles from the roller so that they are sucked into the suction duct 11. In the event that even part 8 tends to be wound up on the roller, it will be blown off in the gap 18, and returned to the position illustrated in the drawing.

In the event that under special circumstances which do not normally occur, the gap 13 is clogged by Waste material, the displaceable portion 14 is released by the resilient arresting means 17, and falls to the position illustrated in broken lines, which may actuate a warning signal calling the operators attention to the machine.

Furthermore, the displaceable wall portion 14 may be opened by the operator for the purpose of removing pieces of the material falling into the suction duct. The examination of the rejected parts of the workpiece is particularly necessary at the beginning of an operation with a new workpiece when the machine is set and adjusted to the operation.

Due to the fact that the front and rear walls of the suction duct 11 are substantially parallel to each other, and also parallel to tangents on substantially diametrically located points of the roller 3, the wast parts of the material flow freely and easily into the suction duct. Particularly, the tangential direction of the front wall portion 14 results in a gap 18 which has the greatest possible effective length and covers the greatest possible are of the peripheral surface of the roller 3. Consequently, the high velocity air stream in the gap 18 is etfective over a substantial portion of the peripheral surface of roller 3.

Since roller 3 is resiliently mounted, and yields when the thickness of the workpiece 6 varies, the width of gap 18 varies slightly during the operation. In a modified embodiment of the invention, the displaceable wall portion 14 is connected to the movable support of roller 3, and moves with roller 3 whenever the same is displaced by the workpiece and the support of roller 3 resiliently yields. In this manner, the width of the gap 18 remains constant even if roller 3 is displaced. During such movcment of the Wall end portion 14, its lateral edges remain in sealing engagement with the inner surfaces of the side walls 12a.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of arrangements for stripping rollers from material adhering thereto diifering from the types described above.

While the invention has been illustrated and described as embodied in a suction stripping arrangement in which air is guided in tangential direction through a narrow gap adjacent a transporting roller which transports a leather sheet toward a splitting cutter, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

l. A suction stripping arrangement comprising, in combination, a cutting tool means; a rolier rotating for transporting a material to said cutting tool whereby the material is cut and partly wound up on said roller; and a suction duct having an inlet portion including a wall, and a wall end portion movably mounted on said wall and having an inoperative position farther spaced from said roller, and an operative position closer spaced from said roller and extending parallel to a tangent on a pcripheral surface portion of said roller moving opposite to the direction of the flow of air in said inlet portion, said end portion defining a narrow gap with said surface portion in said operative position; said cutting tool means, said roller, and the material between said roller and said cutting tool extending across said inlet portion of said duct whereby air is sucked mainly through said gap into said duct'and moves at a high velocity in tangential direction along said surface portion so that cut material adhering to said surface portion and moving opposite to the direction of the air fiow in said gap is stripped off said roller.

2. An arrangement as set forth in claim 1 wherein said wall end portion is pivotally mounted on said wall for turning movement between said inoperative and operative positions; and including means for detachable arresting said wall end portion in said operativ position.

smegma 3. An arrangement as set forth in claim 2 wherein said arresting means include a resilient catch means releasable under the pressure of material Wound up on said roller and accumulating in said gap.

4. A suction stripping arrangement comprising, in combination, a cutting tooi means; a roiler rotating for porting a materia to said cutting tool whereby the material is cut and partly wound up on said roiler; and a suction duct having an inlet portion including a Wall, and a wall end p0: ion movably mounted on said well and having an inoperative position farther spaced from said rolier, and an operative position closer spaced from said roller and extending parallel to a tangent on a peripheral surface portion of said roller moving opposite to the direction of the -flow of air in said inlet portion, end portion defining a narrow gap with said surface portion in said operative position and having a curved extension extending from said gap away from said roller to form with the surface of the same a tapering inlet leading to said gap; said cutting tool means, said roller, and the material between said roller and said cutting tool extending across said inlet portion of said duct whereby air is sucked mainly through said gap to said duct and moves at a high velocity in tangential direction along said surface portion so that cut material adhering to said surface portion and moving opposite to the direction of the air flow in said gap is stripped off said roller.

5. An arrangement as set forth in claim 4- Wherein said inlet portion of said suction duct has another Wall extending substantially parallel toa tangent on a peripheral surface portion of said roller spaced substantially 180 from said first mentioned surface portion.

No references cited. 

